1. Field
This disclosure relates generally to capacitors, and more specifically, to capacitors using an isolated well.
2. Related Art
Capacitors are a commonly used element in circuits and in integrated circuits can require significant space and thus add cost. Also the amount of capacitance corresponds to the amount of space. Further, in many applications it is desirable to know what the capacitance actually is as accurately as possible. Another factor is the speed requirements of the circuit using the capacitor can also place demands on the performance of the capacitor. Also, low power applications will generally put a higher importance on leakage. With many devices being battery operated, this has become more important. Another significant issue is isolating the capacitor from other circuitry. The other circuitry may interfere with the capacitor operation and similarly the capacitor operation may interfere with the other circuitry. Thus, the issues of space, capacitance, speed, leakage, isolation, and precision are potentially significant for any given application. The significance of a given issue will vary with the application.
Accordingly, there is a need for a capacitor that provides the proper combination of features for a particular application while avoiding unduly increasing costs.